diff --git a/doc/fixes3-7-0.txt b/doc/fixes3-7-0.txt
index c6faff6be..f6ffcc5a9 100644
--- a/doc/fixes3-7-0.txt
+++ b/doc/fixes3-7-0.txt
@@ -1147,6 +1147,7 @@ prevent hug attacks and touch or engulf attacks for wrap, stick-to, and
 	digestion damage from succeeding against unsolid targets (ghosts,
 	vortices, a few others)
 wand of speed gives temporary speed, potion gives intrinsic
+some monsters (riders, shopkeepers, priests, quest leader) can break boulders
 
 
 Fixes to 3.7.0-x General Problems Exposed Via git Repository
diff --git a/include/extern.h b/include/extern.h
index e12f290a2..730ee3424 100644
--- a/include/extern.h
+++ b/include/extern.h
@@ -1711,6 +1711,8 @@ extern struct monst *find_pmmonst(int);
 extern int bee_eat_jelly(struct monst *, struct obj *);
 extern void monflee(struct monst *, int, boolean, boolean);
 extern void mon_yells(struct monst *, const char *);
+extern boolean m_can_break_boulder(struct monst *);
+extern void m_break_boulder(struct monst *, coordxy, coordxy);
 extern int dochug(struct monst *);
 extern boolean m_digweapon_check(struct monst *, coordxy, coordxy);
 extern int m_move(struct monst *, int);
diff --git a/src/mon.c b/src/mon.c
index 232abc976..c2e32f134 100644
--- a/src/mon.c
+++ b/src/mon.c
@@ -1829,7 +1829,7 @@ mon_allowflags(struct monst* mtmp)
         allowflags |= ALLOW_SSM | ALLOW_SANCT;
     if (passes_walls(mtmp->data))
         allowflags |= (ALLOW_ROCK | ALLOW_WALL);
-    if (throws_rocks(mtmp->data))
+    if (throws_rocks(mtmp->data) || m_can_break_boulder(mtmp))
         allowflags |= ALLOW_ROCK;
     if (can_tunnel)
         allowflags |= ALLOW_DIG;
diff --git a/src/monmove.c b/src/monmove.c
index f3b760a0d..f8f97c59d 100644
--- a/src/monmove.c
+++ b/src/monmove.c
@@ -104,6 +104,36 @@ mon_yells(struct monst* mon, const char* shout)
     }
 }
 
+/* can monster mtmp break boulders? */
+boolean
+m_can_break_boulder(struct monst *mtmp)
+{
+    return (is_rider(mtmp->data)
+            || (!mtmp->mspec_used
+                && (mtmp->isshk || mtmp->ispriest
+                    || (mtmp->data->msound == MS_LEADER))));
+}
+
+/* monster mtmp breaks boulder at x,y */
+void
+m_break_boulder(struct monst *mtmp, coordxy x, coordxy y)
+{
+    struct obj *otmp;
+
+    if (m_can_break_boulder(mtmp) && ((otmp = sobj_at(BOULDER, x, y)) != 0)) {
+        if (!is_rider(mtmp->data)) {
+            if (!Deaf && (mdistu(mtmp) < 4*4))
+                pline("%s mutters %s.",
+                      Monnam(mtmp),
+                      mtmp->ispriest ? "a prayer" : "an incantation");
+            mtmp->mspec_used += rn1(20, 10);
+        }
+        if (cansee(x, y))
+            pline_The("boulder falls apart.");
+        fracture_rock(otmp);
+    }
+}
+
 static void
 watch_on_duty(register struct monst* mtmp)
 {
@@ -1536,6 +1566,11 @@ m_move(register struct monst* mtmp, register int after)
         if (!m_in_out_region(mtmp, nix, niy))
             return MMOVE_DONE;
 
+        if ((info[chi] & ALLOW_ROCK) && m_can_break_boulder(mtmp)) {
+            (void) m_break_boulder(mtmp, nix, niy);
+            return MMOVE_DONE;
+        }
+
         /* move a normal monster; for a long worm, remove_monster() and
            place_monster() only manipulate the head; they leave tail as-is */
         remove_monster(omx, omy);
diff --git a/src/priest.c b/src/priest.c
index 8560d0c6b..00779be5c 100644
--- a/src/priest.c
+++ b/src/priest.c
@@ -101,7 +101,10 @@ move_special(struct monst *mtmp, boolean in_his_shop, schar appr,
 
     if (nix != omx || niy != omy) {
 
-        if (ninfo & ALLOW_M) {
+        if (ninfo & ALLOW_ROCK) {
+            m_break_boulder(mtmp, nix, niy);
+            return 1;
+        } else if (ninfo & ALLOW_M) {
             /* mtmp is deciding it would like to attack this turn.
              * Returns from m_move_aggress don't correspond to the same things
              * as this function should return, so we need to translate. */